Lever-type two-cycle internal combustion engine

ABSTRACT

An internal combustion engine having opposed power cylinders and separate air or air-fuel charging cylinders, and a lever system interconnecting the power and air or air-fuel charging cylinder pistons with each other and with a crankshaft. The lever system comprises the piston rods of the power and air or air-fuel pistons, each piston rod being pivotally connected at one end to its respective piston and being pivotally connected at its opposite end to the corresponding opposite ends of the other two piston rods. One of said piston rods-namely, the piston rod of the air or air-fuel charging cylinder-is connected intermediate its ends to a crankshaft and said piston rod accordingly functions as the lever which drives the crank arm of the engine.

United States Patent Edward C. Wenzel 553 W. Shore Trail, Sparta, NJ.07871 15,999 I Mar. 3, 1970 Sept. 28,1971

[72] Inventor [21 Appl. No. [22] Filed [45] Patented [54] LEVER-TYPETWO-CYCLE INTERNAL COMBUSTION ENGINE 10 Claims, 16 Drawing Figs.

52 user 123/56BC s11 1m.c1 mums/24 s01 FieldofSearc 123/56B,

[56] References Cited UNITED STATES PATENTS 7/1886 Smith l0/l9l2 Sailer123/56 BC 123/56 BC FOREIGN PATENTS 510,522 10/1930 Germany l,093,l02ll/l954 France Primary ExaminerWendell E. Burns Attorneys-Stoll andStoll 123/56 BC l23/56 BC ABSTRACT: An internal combustion engine havingopposed power cylinders and separate air or air-fuel charging cylinders,

and a lever system interconnecting the power and air or air- -fuelcharging cylinder pistons with each other and with a crankshaft. Thelever system comprises the piston rods of the power and air or air-fuelpistons, each piston rod being pivotally connected at one end to itsrespective piston and being pivotally connected at its opposite end tothe corresponding opposite ends of the other two piston rods. One of fsaid piston rods-namely, the piston rod of the air or air-fuel chargingcylinderis connected intermediate its ends to a crankshaft and saidpiston rod accordingly functions as the lever which drives the crank armof the engine.

il/on la e lag PATENTED sme 1971 SHEET 07 0F 11 PM'ENTEUSEPZBISTI3.608.530

saw 09 or 11 INVIQN'IOR. EDWARD 6. WENZE'L PATENTED SEP28 19?:

SHEET 100F11 INVIaN'I'OIC. EDWARD E. WENZEL PAIENTED m um 3508.530

' sum 11 0F 11 INVIa'NI'OIa. EDWARD C. WENZEL LEVER IYPE TWO-CYCLEINTERNAL COMBUSTION ENGINE BACKGROUND OF THE INVENTION l. Field of theInvention Lever-type internal combustion engines, whether based ongasoline or diesel engine principles.

2. Description of the Prior Art The use of lever-type engines dates backto the early days of automotive and internal combustion enginedevelopment. Historic advances in engine design necessarily include thebrainchild of Alvah A. Powell, who saw advantages in changing longstroke piston travel to shorter crank throwthrough leverage. More recentimprovements include opposed cylinder two-cycle engines such as the typedisclosed in US. Pat. No. 2,445,720 to Wenzel.

Known engines, however, include many undesirable features whichdesigners in the art have unsuccessfully sought to overcome. Relativelycomplicated linkages with long connecting rods are characteristic ofengines known to the art. In addition, vibration problems created byimbalance of moving parts result in a loss of engine efiiciency as wellas ever increasing engine w ear. The use of flywheels mounted on theends of crankshafts and equipped with counterbalance weights have onlyadded to already complicated engine structures.

SUMMARY OF THE INVENTION This invention relates to two-cycle internalcombustion engines. The same principle, although not-here specified, maybe used in external combustion engines such as steam engines, in which arelatively large stroke-to-bore ratio is desirable for increasingcrankshaft torque. The invention will, however, be described herein inrelation to a two-cycle internal combustion engine, but this descriptionis not intended to limit the application of the invention except to theextent and scope of the appended claims.

Specifically, in the present invention the power cylinders are axiallyaligned in opposed positions, the piston rod of each said power (work)cylinder being pivotally connected at its outer end to the correspondingend of the piston rod of the opposed power cylinder. An air or air-fuelcharging cylinder is provided for each pair of opposed power cylinders.Its longitudinal axis intercepts the common longitudinal axis of the twopower cylinders at right angles thereto. In the preferred form of thisinvention the opposed power cylinders occupy a common horizontal plane.The air or air-fuel charging cylinder extends vertically, itslongitudinal axis being normal to said horizontal plane.

The piston rod of the air or air'fuel charging cylinder is connected atits outer (lower) end to the connected outer ends of the piston rods ofthe horizontally opposed power cylinders. The relationship of all threepiston rods to their respective pistons and to each other is the same inall three cases-that is, the inner end of each piston rod is pivotallyconnected to its respective piston, and the outer end of each piston rodis pivotally connected to the corresponding outer ends of the other twopiston rods.

The crankshaft is located above the horizontally opposed power cylindersand below the vertically extending air or airfuel charging cylinder. Thepiston rod of the air or air-fuel charging cylinder is connected,intermediate its ends, to the offset crank pin of the crankshaft.Accordingly, for the purposes of this description, the piston rod of theair or air-fuel charging cylinder may be considered to be the operativelever of the lever system of the present invention. In this arrangement,the inner end of the lever (connected to the piston rod of the air orair-fuel charging cylinder) is its fulcrum end; the outer end of saidlever (which is connected to the outer ends of the piston rods of thepower cylinders) may be considered to be its effort end; and theintermediate connection between the lever and the crankshaft may beconsidered to be the load or work-applying portion of the lever.

It will be understood from this description and from the appendeddrawing that there is no fixed axis for any part of the lever. Thefulcrum moves linearly in a vertical line, reciprocating between upperand lower positions. The loador work-applying portion of the leverrotates in a circular path about the crankshaft axis. The effort end ofthe lever describes an orbital path.

The principal object of this invention is the provision of a lever-typeengine of the character described, wherein the power or work cylindersare axially aligned and opposed to provide a direct thrust, inertiaabsorbing cushion in each cylinder of each pair of opposed cylinders,thereby freeing the crankshaft from excessive inertial loading, andrendering it feasible to provide a relatively large stroke-to-bore ratioin the power cylinders.

It is an object of this invention to provide a lever-type engine of thecharacter described which employs the slidable fulcrum principle inorder to-produce a relatively large stroke-tobore ratio in the powercylinders, while employing a small crank arm radius and relatively shortconnecting linkages between the pistons and the crankshaft.

Another object of the invention is to increase piston dwell time at eachend of the power piston stroke, thereby increasing the time forhomogenization of the air-fuel mixture to promote more completecombustion within the power cylinder at the end of the compressionstroke and beginning of the power stroke, and more complete scavengingand recharging at the end of the power stroke and beginning of thecompression stroke.

A further object of this invention is to provide, within feasible totalvolume, an engine having a long piston stroke relative to the cylinderdiameter to promote more complete combustion of the air-fuel mixturetaken into the cylinder such that pressure and combustion levelsapproach zero value before the exhaust port is opened at the end of thepower stroke.

A still further object of the invention is to provide an internalcombustion engine which will produce minimum exhaust pressure andparticle emission to minimize air pollution.

The present invention provides a lever engine comprising a plurality ofpower cylinders (preferably in multiples of four or eight) arranged inpairs in such manner that the cylinders of each pair are directlyopposed in coaxial relationship in a horizontal plane. In aneight-cylinder engine as herein shown and described, there are fourpairs of opposed cylinders arranged side by side in parallelrelationship in a common horizontal plane. There is a single air orair-fuel charging cylinder for each pair of opposed power cylinders, andin an engine having four pairs of opposed power cylinders (eightcylinders in all) there are four charging cylinders. These chargingcylinders are arranged side by side in parallel relationship, in acommon vertical plane, the axes of said charging cylinders extendingvertically and intercepting the power cylinder axes at right angles. Thecrankshaft extends horizontally in the vertical plane which the chargingcylinders occupy, and in a horizontal plane above the horizontal planewhich the opposed power cylinders occupy. The crankshaft has four crankarms which are equally spaced from each other at intervals, there beingone crank arm for each pair of opposed cylinders. Power is delivered tothe crankshaft by at least two power cylinders at all times. Each air orair-fuel charging cylinder supplies two power cylinders with air or anair-fuel mixture, there being four charging cylinders and eight powercylinders. Each charging cylinder will communicate with two powercylinders when their respective inlet ports are opened at the end of apower or work stroke. At such time the piston of the charging cylinderwill reach its extreme upper position in its upwardly moving compressionstroke, so as to deliver. the required charge of air or air-fuel mixtureto the two power cylinders with open inlet ports.

As has above been stated, the lever system of each pair of opposed powercylinders and their adjacent charging cylinder comprises the piston rodsof the three cylinders pivotally connected to each other at theirrespective outer ends. The piston rod of the charging cylinder isconnected intermediate its ends to the Crankshaft, and accordingly maybe deemed and designated the lever of the lever-type engine hereindescribed and claimed. The charging cylinder (piston) performs twofunctions:

l. It provides compressing means for compressing air or an air-fuelmixture and delivering same to the power cylinders.

2. It provides a vertically reciprocating fulcrum for the lever whichdrives the crankshaft.

It is this arrangement, wherein the three piston rods (of each pair ofwork cylinders and one air-charging cylinder) comprise the entire leversystem of the engine, that renders it possible to dispense with thecomplicated lever systems and linkages of the lever engines of the priorart. It is the use of the pivotal connection between the piston of theair-charging cylinder and its piston rod as the fulcrum of the leversystem that makes it possible to dispense with the supplemental fulcrumsystems of prior engines.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a plan view of aneight-cylinder, two-cycle engine made in accordance with the principlesof this invention.

FIG. 2 is a section through a vertical plane which is parallel to theaxis of the crankshaft and taken on the line 2-2 of FIG. 12.

FIG. 3 is a second vertical section corresponding to FIG. 2 but taken onthe line 3-3 of FIG. 13.

FIG. 4 is a third vertical section corresponding to FIG. 2 but taken onthe line 4-4 of FIG. 14.

FIG. 5 is a fourth vertical section corresponding to FIG. 2 but taken onthe line 5-5 of FIG. 15.

FIG. 6 is a fifth vertical section corresponding to FIG. 2 but taken onthe line 6-6 of FIG. 16.

FIG. 7 is a section through a vertical plane which is at right angles tothe axis of the crankshaft and is taken on the line 7- 7 of FIG. 2.

FIG. 8 is a second vertical section corresponding to FIG. 7 but taken onthe line 8-8 of FIG. 3.

FIG. 9 is a third vertical section corresponding to FIG. 7 but taken onthe line 9-9 of FIG. 4.

FIG. 10 is a fourth vertical section corresponding to FIG. 7 but takenon the line 10-10 of FIG. 5.

FIG. 11 is a fifth vertical section corresponding to FIG. 7 but taken onthe line 11-11 of FIG. 6.

FIG. 12 is a section through a horizontal plane and taken on the line12-12 of FIG. 2.

FIG. 13 is a second horizontal section corresponding to FIG. 12 buttaken on the line 13-13 of FIG. 3.

FIG. 14 is a third horizontal section corresponding to FIG. 12 but takenon the line 14-14 of FIG. 4.

FIG. 15 is a fourth horizontal section corresponding to FIG. 12 buttaken on the line 15-15 of FIG. 5.

FIG. 16 is a fifth horizontal section corresponding to FIG. 12 but takenon the line 16- 16 of FIG. 6.

DESCRIPTION OF PREFERRED EMBODIMENT OF THE INVENTION Referring now tothe details of the invention as illustrated in the drawing, it will beobserved that there are four pairs of power cylinders, eight powercylinders in all, designated respectively as follows: 10a and 10b, 12aand 12b, 14a and 14b, and 16a and 16b. Associated with these four pairsof power cylinders are four air or air-fuel charging cylinders,designated respectively 100. 12c, 14c and 160. A housing 20 supports thepower and charging cylinders in the arrangement shown in the drawing,and it will shortly be described. Also supported by and within thehousing is a crankshaft 22, there being only one crankshaft for theeight power cylinders and the four charging cylinders.

It will now be observed that the eight power cylinders are disposed in acommon horizontal plane, each pair of said cylinders being coaxiallyaligned and opposed, the four pairs of opposed cylinders being arrangedin side-by-side relationship so that the longitudinal axis of each pairis parallel to the longitudinal axes of the other three pairs. Thecharging cylinders are also arranged in side-by-side relationship, theirrespective longitudinal axes being disposed in parallel relationship toeach other in a common vertical plane centered between power cylinders10a, 12a, 14a and 160, on the one hand, and power cylinders 10b, 12b,14b and 16b, on the other hand. The longitudinal axis of crankshaft 20also lies in the vertical plane of the charging cylinders, and it isalso disposed in a horizontal plane located between the power cylinderson the one hand and the charging cylinders on the other.

It will be understood that the power cylinders are respectively providedwith pistons and piston rods designated as follows:

power cylinder 10a-piston 10d, piston rod 102 power cylinder 10b-piston10f, piston rod 10g power cylinder 12a-piston 12d, piston rod 12e powercylinder 12b-piston 12f, piston rod 12g power cylinder 14a-piston 14d,piston rod l4e power cylinder l4b-piston 14f, piston rod 14g powercylinder 16a-piston 16d, piston rod 16 power cylinder 16b-piston 16f,piston rod 16g By the same token, the air or air-fuel charging cylindersare also provided with pistons and piston rods designated as follows:

charging cylinder 10cpiston 10h, piston rod 10! charging cylinder 12c-piston 12h, piston rod 12i charging cylinder l4c-piston 14h, piston rod14i charging cylinder 16cpiston 16h, piston rod 161' The crankshaft 22has four crank pins spaced at intervals and designated as follows:

for piston rod 10icrankpin 22a for piston rod l2icrankpin 22b for pistonrod 14i-crankpin 22c for piston rod 16i-crankpin 22d With furtherreference to the details of the invention as illustrated in the drawing,it will be noted that the power cylinders are provided with heatexchange fins 24. It will thereby be understood that the preferredembodiment of the invention is an air-cooled engine. However, it shouldalso be understood that the invention is not intended to be limited toair-cooled engines, and the principles of the invention may equally beapplied to engines which are water-cooled.

It will further be noted that the power cylinders are long in relationto the diameter of their respective pistons, that is, the length of thestroke of the power pistons exceeds their diameter. This is known as anundersquare design, and the ratio of stroke-to-bore may exceed 1:1 toany desired extent, even as high as approximately 2:], as schematicallyshown in the drawing. The invention is not limited to any specificstroke-tobore ratio.

The mechanical linkages which are significant in the execution of thisinvention are the following: The pistons rods of the several powercylinders are pivotally connected at their inner ends to theirrespective pistons by means of cross pins 26. The piston rods of eachpair of power cylinders are pivotally connected to each other by meansof cross pins 28. Similarly, the piston rods of the several air chargingcylinders are pivotally connected at their inner ends to theirrespective pistons by means of cross pins 30. At their outer ends thepiston rods of the air charging cylinders are pivotally connected to theouter ends of the piston rods of the power cylinders by means of abovementioned pin 28. It will accordingly be understood that the severalpiston rods of the power and air charging cylinders are pivotallyconnected at their inner ends to their respective pistons and pivotallyconnected at their outer ends to each other.

The piston rods of the air charging cylinders are also connected to thecrankshaft. More particularly, piston rod 101' is rotatably connected tocrank pin 22a, piston rod 121' is rotatably connected to crank pin 22b,piston rod 141' is rotatably connected to crank pin 22c, and piston rod161' is rotatably connected to crank pin 22d. The crankshaft is, ofcourse, adequately supported by bearings in any conventional manner.schematically it is indicated in the drawing that the housing isprovided with five bearing blocks, 32, 32a, 32b, 32c and 32d,respectively, suitable split bearing sleeves 34, 34a, 34b, 34c and 34dare provided to support the crankshaft on said bearing blocks. Spacersleeves 36 are provided where necessary. However, it will be understoodthat the drawing is primarily schematic and the showing of the severalworking parts is exaggerated for purposes of clarity, and relativeproportions of the parts as shown in the drawing should not be takenliterally. This is particularly true of the crankshaft, including thespacing between the bearing supports and the crank pins.

As has above been indicated, this invention is primarily applicable totwo-cycle internal combustion engines, and the engine which is shown inthe drawing illustrates this application of the invention. There is novalve system connected with the power cylinders other than open portsformed in those cylinders and the pistons themselves, which open andclose the ports. Specifically, each power cylinder is provided with aninlet port 40 and an outlet or exhaust port 42. The inlet ports of theseveral power cylinders are connected to the air charging cylinders bymeans of suitable tubes, as will shortly be described. The outlet orexhaust ports are connected to an exhaust manifold and exhaust pipe,neither of which is shown in the drawing because it is entirelyconventional.

It ill be noted that the inlet ports 40 are of smaller diameter than theoutlet or exhaust ports 42. In the preferred form of this invention, theinlet and outlet ports are not coaxial, but they do register with eachother to the extent of the diameter of the inlet ports. When a powerpiston reaches its extreme outermost position relative to the cylinderin which it is housed, as for example piston d in cylinder 10a, as shownin FIG. 7, both ports 40 and 42 are fully open. When the piston occupiesa less extreme outer position, as does piston 10d in cylinder 10a inFIG. 11, inlet port 40 is closed while outlet port 42 is partly open andpartly closed. Depending upon the direction of movement of the pistonrelative to these two ports, outlet port 42 may first open and theninlet port 40, or inlet port 40 may first close and then outlet port 42.

The significance of this opening and closing sequence is the following:When a power piston, e.g., power piston 10d, moves outwardly in itspower stroke, outlet port 42 first opens to allow the combustion gasesto escape. This occurs immediately before the piston reaches itsoutermost position relative to the cylinder in which it is disposed. Bythe time the outermost position is reached, inlet port also opens, andthis enables an inward rush of air to scavenge the cylinder and therebydrive the remaining combustion gases out of the cylinder through outletport 42. The combustion gases are thereby replaced by a fresh charge ofair or air-fuel mixture, as the case may be. When the piston nowreverses its stroke and moves inwardly relative to the cylinder in whichit s mounted, inlet port 40 closes, thereby shutting off the supply ofair or air-fuel mixture. Further inward movement of the piston closesthe outlet port, and the fresh charge of air or air-fuel mixture may nowbe compressed. This sequence and the functional relationship between thepower and air charging cylinders will shortly be discussed in greaterdetail to describe the functioning of the entire engine.

In the two-cycle engine which is illustrated in the drawing, thefunction of the air charging cylinders is to scavenge and recharge thepower cylinders. It will be observed that each air charging cylinder hasan inlet port 44 and an outlet port 46. The inlet port communicates withthe atmosphere to receive air, or with a carburetor to receive anair-fuel mixture. A check valve 48 is provided at inlet port 44 in orderto allow air or an air-fuel mixture to enter the air charging cylinderand said check valve automatically closes to prevent discharge of theair or air-fuel mixture from said cylinder. A second check valve 50 isprovided at outlet port 46, and its function is to allow the air orair-fuel mixture to leave the cylinder, and it automatically closes toprevent a reverse flow through outlet port 46 when the air chargingcylinder is in process of receiving a fresh charge of air or air-fuelmixture. It will be understood (and it will be seen in the drawing,e.g., in FIG. I) that each air charging cylinder is connected to twopower cylinders. Accordingly, it is desirable to provide a Y-typefitting at the outlet port 46 of each air charging cylinder, the twobranches of the Y-fitting being connected by suitable tubing to the twopower cylinders with which each air charging cylinder is associated. Therelationship between the several air charging cylinders on the one handand power cylinders on the other, and the air lines between the twogroups of cylinders, are shown pictorially in FIG. 1 of the drawing andschematically in FIGS. 12, 13, 14, 15 and 16. In FIG. 1, as well as inFIGS. 12 through 16, it is shown that air charging cylinder 10c isconnected by means of air lines 60a and 60b to power cylinders 14a and16b respectively. It is similarly shown that air charging cylinder 12cis connected by means of air lines 62a and 62b to power cylinders 16aand 14b, respectively. Air charging cylinder 140 is connected by meansof air lines 64a and 64b to power cylinders 12a and 10b, respectively.And finally, air charging cylinder 16c is connected by means of airlines 66a and 66b to power cylinders 10a and 12b, respectively. It is ofcourse understood that these several air lines are connected between theoutlet ports 46 of the air charging cylinders and the inlet ports 40 ofthe power cylinders. Accordingly, each air charging cylinder isconnected to and is responsible for the scavenging and recharging of twopower cylinders.

It will also be understood that the power cylinders require not only airbut also fuel and means for igniting the air-fuel mixture. If the enginewhich embodies the present invention is a gasoline fuel internalcombustion engine, it has one or more carburetors or other air-fuelmixing and feeding devices. Assuming the existence and use of acarburetor, it will be understood that is is connected to the severalair charging cylinders and that they supply the power cylinders with anair-fuel mixture. Ignition would require the use of spark plugs 66. Onthe other hand, if the invention is embodied in a diesel engine, the aircharging cylinders would supply only air to the power cylinders, andfuel would be injected into said power cylinders by means of fuelinjectors 68.

It will also be understood, and it is clearly shown in the drawing, thatthe air charging cylinder which is mechanically connected to a givenpair of power cylinders is not connected to those particular powercylinders for air supply. As an illustration, FIG. 7 shows a pair ofpower cylinders 10a and 10b and an air charging cylinder 10cmechanically connected to said power cylinders through their respectivepistons and piston rods. However, air charging cylinder 10c does notsupply air to power cylinders 10a and 10b. Instead, as has above beenindicated and as is shown in FIG. 1 and FIGS. 12 to 16, inclusive, aircharging cylinder is connected by air lines 60:: and 60b to powercylinders 16a and 14b.

The mechanical operations of a representative pair of power cylindersand the air charging cylinder which is mechanically associated therewithwill now be described. FIGS. 7, 8, 9, 10 and 11 depict the variousstages in a cycle involving the pistons and piston rods of powercylinders 10a and 10b and air charging cylinder 100. In all of thosefigures the crankshaft rotates in counterclockwise direction, asindicated by curved arrows 70.

Starting with FIG. 7, it will be noted that power piston 10d is at itsextreme outer position following a power stroke and power piston 10f isat its innermost position following a compression stroke. Ports 40 and42 in cylinder 10a are now open, so that the combustion gases may escapethrough the outlet port 42 and the fresh charge of air may enter throughinlet port 40. The inrush of fresh air completes the evacuation ofcombustion gases and fills the cylinder. At thesame time, the air orair-fuel mixture within power cylinder 10b is compressed preparatory toa power stroke of piston 10f. Ignition occurs, e.g., by the use of sparkplug 66, and an explosion takes place within power cylinder 10b.

In the meantime, piston 10h in air charging cylinder 100 is movingupwardly, and is thereby expelling air from said air' charging cylinderthrough open valve 50 and driving it into power cylinders 16a and 14b.

The next stage in the operation is shown in FIG. 8. Pistons 10d and 10fnow move leftwardly, an explosion having taken place in cylinder 10bdriving piston 10f outwardly therefrom and compression taking placeconcurrently therewith in cylinder 10a. Air charging piston 10h has nowmoved to its extreme uppermost position in cylinder 10c, and this marksthe end of its air charging operation with respect to power cylinders16a and 14b.

The next stage in the operation is shown in FIG. 9, wherein power piston10d has reached its extreme inward position in cylinder 10a and powerpiston 10f has reached its outermost position in cylinder 10b. This isthe reverse of their respective positions as shown in FIG. 7. The outletport 42 of cylinder 10b is opened first to start the exhaust of thecombustion gases from said cylinder, and inlet port 40 then opens toreceive a fresh charge of air from air charging cylinder 140. As hasabove been indicated, the inrush of fresh air completes the process ofexhausting the combustion gases and the fresh air accordingly takes theplace of the combustion gases in power cylinder 10b. On the opposed sidepower piston 10d has reached its innennost position wherein itcompresses the air in cylinder 10a. Since it is assumed that acarburetor is being used, a suitable charge of fuel is entrained withthe air, and what is compressed in cylinder 10a is a combustibleair-fuel mixture.

At the same time piston 10h moves downwardly in air charging cylinder10c, and it is thereby drawing a fresh charge of air into said cylinderthrough open valve 48.

The next stage in the operation is shown in FIG. 10, wherein the powerpistons are depicted moving rightwardly. Specifically, combustion hasstarted in power cylinder 10a, driving piston 10d outwardly therefromand forcing piston 10f inwardly relative to cylinder 10b. Since cylinder10b has received a charge of fresh air entrained with fuel, piston 10fis now in the process of compressing same into an explosive mixture.Piston 10h has now reached its outermost position in cylinder 10c, andit has drawn a full charge of air, entrained with fuel, into saidcylinder. Cylinder 100 is now ready to deliver a fresh charge of air andfuel to the power cylinders 16a and 14b with which it is connected.

FIG. 11 depicts the next stage in the operation, just short of thestarting stage shown in FIG. 7. The expansion of the combustion gases incylinder 10a continues to drive power cylinder 10d outwardly, but is hasnot yet reached its outermost position shown in FIG. 7. By the sametoken, piston 10bf is moving toward its extreme innermost position incylinder 10b, but it is still short of the starting position which isshown in FIG. 7. More particularly, piston 10d has moved outwardly asufficient distance to partially open the outlet port 42 in cylinder10a, but inlet port 40 in said cylinder remains closed. Accordingly, thecombustion cases in cylinder 10a begin to exhaust out of said cylinder,but they are not yet being forced out of the cylinder by the inrush of anew charge of air. On the opposite side piston 10f is compressing theair-fuel mixture in cylinder 10b, but compression has not yet beencompleted.

Piston 10h is again moving upwardly in air charging cylinder 10c, and itis driving air entrained with fuel out of said cylinder through openvalve 50 and into cylinders 16a and 14b. The final stage in theoperation is the same as the initial stage depicted in FIG. 7. Onecomplete cycle has now been concluded, and the next cycle is about tobegin.

The relationship among the several air charging cylinders and the mannerin which their respective piston rods operate upon the crankshaft may beseen in FIGS. 2, 3, 4, and 6. These figures coincide with FIGS. 7, 8, 9,and 11. In the sense that the several stages of the pistons shown inFIGS. 7, 8,

'9, 10 and 11 correspond identically to their stages in FIGS. 2,

position in FIG. 4 which it occupies in FIG. 9, the same position inFIG. 5 which it occupies in FIG. 10, and the same position in FIG. 6which it occupies in FIG. 11. By the same token, power pistons 10d and10f occupy the same positions in their respective cylinders 10a and 10bin FIG. 7 which they occupy in FIG. 12, the same positions in FIG. 8which they occupy in FIG. 13, the same positions in FIG. 9 which theyoccupy in FIG. 14, the same positions in FIG. 10 which they occupy inFIG. 15, and the same positions in FIG. 11 which they occupy in FIG. 16.It will similarly be understood that FIGS. 2 through 6 are verticalsections (at least in part) of FIGS. 12 through 16. Consequently, therelative positions of all of the pistons shown or indicated in FIGS. 2through 6 correspond t the relative positions of the same pistons inFIGS. 12 through 16.

Selecting FIG. 2 for illustrative purposes, it ill be seen that piston10h occupies the same position in cylinder of FIG. 2 which it occupiesin FIG. 7, piston 12h occupies the same position in cylinder 12c of FIG.2 which it occupies in FIG. 9, piston 14h occupies the same position incylinder 14c of FIG. 2 which it occupies in FIG. 10, and piston 16hoccupies the same position in cylinder of FIG. 2 which it occupies inFIG. 8. The same may be said of FIGS. 3 through 6. Each of the pistonsof each of the air charging cylinders shown in FIGS. 3 through 6 isshown in a position which corresponds to one of the positions shown inFIGS. 7 through 11.

The operation of the engine may best be understood from FIGS. 12 through16 and their corresponding vertical sections shown in FIGS. 2 through 6.

Turning now to FIG. 12, it will be understood that power cylinders 10aand 12b are shown receiving a charge of air entrained with fuel, fromair charging cylinder 160. This is evidenced by heavy lines 66a and 66band the arrowheads which are superimposed upon them. This processcompletes the exhaustion of the combustion gases from said cylinders andrecharges them with an air-fuel mixture preparatory to the combustionstroke.

Concurrently with the air charging operation last described, thecompressed air-fuel mixture in cylinder 12a ignites and commences toburn to begin the power stroke of the piston in that cylinder. This isequally true of the compressed air-fuel mixture in cylinder 10b, and theignition of this mixture commences the power stroke of the piston inthat cylinder. It will therefore be observed that since the pistons incylinders 10a and 10b are opposed and connected through their respectivepiston rods, and since the pistons in cylinders 12:: and 12b are alsoopposed, the last described power strokes commencing in cylinders 12aand 10b will produce compression strokes in cylinders 12b and 10a.

Also concurrently with the foregoing expansion of the combustion gasesin cylinders 14a and 16b causes compression of the air-fuel mixtures incylinders 14b and 16a. The direction of movement of the several pistonsin FIGS. 12 is shown by the arrows which relate to them.

FIG. 13 represents the next phase in the operation ofthe engine. In thisfigure cylinders 14a and 16b are shown receiving a charge of airentrained with fuel, and once again the inrush of this flow completesexhaustion of the combustion gases of the prior power stroke andintroduces into the cylinders a fresh charge of such air-fuel mixture.At the same time, the compressed air-fuel mixture in cylinders 14b and16a ignites, and the expanding combustion gases begin the power strokesof the pistons in those cylinders. Also concurrently therewith, theexpanding combustion gases in cylinders 10] and 12b continue the powerstrokes of the pistons in those cylinders and produce compressionstrokes of the pistons in cylinders 10b and 12a.

an air-fuel mixture and the compressed air-fuel charges in 1 cylinders10a and 12b are now ignited in said cylinders to begin the power strokeof the pistons therein. Such power stroke will of course result incompression of the fresh charges in cylinders 10b and 12a. Concurrentlywith the foregoing, the expanding combustion gases in cylinders 14b and16a are producing a power stroke of the pistons in those cylinders,resulting in compression strokes of the pistons in cylinders 14a and16b.

The next stage in the operation of the engine is shown in FIG. 15. Herefresh charges of air entrained with fuel are entering cylinders 14b and16a, while the compressed charges in cylinders 14a and 16b are ignitingto begin the power stroke of the pistons in said cylinders Ma and 1612.As has above been indicated, this will produce compression strokes ofthe pistons in cylinders 14b and 16a. Concurrently therewith, the powerstroke of the pistons in cylinders 10b and 12a is proceeding, as isthecompression stroke of the pistons in opposed cylinders 10a and 121).

FIG. 16 shows the next stage in the operation of the engine, wherein thepistons in cylinders 10a and 12b are shown approaching, but notreaching, the end of their respective power strokes. The exhaust portshave been opened, but not the inlet ports. Accordingly, the combustiongases are now escaping from these cylinders, but they are not fullyexpelled therefrom until the pistons reach the end of their power strokeand thereby open the inlet ports to admit a fresh charge of airentrained with fuel. It is this fresh charge that fully exhaust thesetwo cylinders of their combustion gases. The pistons in opposedcylinders 10b and 12a are concurrently approaching, but not reaching,the end of their compression stroke. Also, the power stroke of thepistons in cylinders 14a and 16b is continuing, while the compressionstroke of the pistons in cylinders 14b and 16a is concurrentlyproceeding. When the pistons 10a and 12b reach the end of their powerstroke, they and all of the other pistons shown in FIG. 16 will occupythe same relative positions as they are shown to occupy in FIG. 12,thereby concluding one complete cycle and commencing the next.

It will be seen, particularly in FIGS. 7 through 10 of the drawing, thatthe crankshaft is shown in four successive angular positions, spaced 90apart. At each angular position of the crankshaft two of the eight powercylinders are engaged in their respective power strokes. It followsthat, for every revolution of the crankshaft, four separate andsuccessive power thrusts are delivered to it, each delivered by twoseparate and spaced power pistons situated 180 apart. This arrangementmakes for a nicely balanced engine with smooth operation and asubstantially continuous flow of power.

The relatively long stroke-small bore design provides a relatively hightorque output at a relatively low r.p.m. The length of the power pistonstroke is twice the length of the crankshaft throw (diameter of thecircular path described by the crankpins). This is effected through theuse of the piston rod of the air charging cylinder as a lever betweenthe piston rods of the power cylinders and the crankshaft. Accordingly,the power pistons apply twice the leverage upon the crankshaft whichthey would apply if connected directly thereto. This is clearly apparentfrom FIGS. 7 through 11 of the drawing.

The long stroke small bore design also provides an improved surface(piston area) to cylinder volume ratio which, when combined with thelonger piston dwell during initial combustion stages, lengthens time inmilliseconds before quenching begins, to promote more completecombustion during the work stroke.

This will be evident from a study of FIGS. 7 through 11 of the drawing.It will there be seen that opposed power pistons 10d and 10f are notalways the same distance apart. When their respective piston rods 10::and 10g are axially aligned, as

in FIGS. 7 and 9, the pistons are at their extreme outer posi tionsrelative to each other. When these piston rods are inclined toward eachother at the smallest angle which the geometry of the system willpermit, as in FIGS. 8 and 10, the

pistons are at their extreme inner positions relative to each other.

It will also be understood that these opposed power pistons traveltoward and away from each other concurrently with their joint movementin the same direction. Thus, when the crankshaft rotates L from its FIG.7 to its FIG. 8 position, the power pistons will move toward each otherat the same time that they are both moving leftwardly. Stateddifferently, power piston 10d will move leftwarclly at a slower speedthan piston 10], so that in relation to each other the two pistons willbe moving toward each other.

By the same token, when the crankshaft rotates an additional 90 thistime from its FIG. 8 to its FIG. 9 position, the two power pistons 10dand 10f will move away from each other concurrently with their continuedjoint movement leftwardly. When the crankshaft rotates a further 90 fromits FIG. 9 to its FIG. 10 position, the power pistons 10d and 10f willmove toward each other at the same time that they are both movingrightwardly. When the crankshaft rotates an additional 90 from its FIG.10 to its FIG. 7 position, completing a 360 revolution, the said powerpistons will move away from each other concurrently with their jointcontinued movement toward the right.

As has above been indicated, one of the consequences of thisrelationship between the power pistons is that longer piston dwell isattained during initial combustion stages and hence more completecombustion.

The foregoing is illustrative of a preferred form of the invention, andit will of course be understood that the invention encompasses extensivedesign modifications within the broad scope of the appended claims. Forexample, what is shown is an air-cooled engine with fins 24 serving asheat exchangers for the charging cylinders. Obviously the invention isequally applicable to a liquid-cooled engine. Similarily, the powerpistons are shown formed with a protuberance 74 for enhanceddistribution of the air-fuel mixture and more uniform combustionthereof. Clearly, modifications in this design, and even the omission ofany such protuberance, would fall within the range and scope of theprinciples of this invention and the appended claims. Nor is theinvention limited to the particular dimensions and proportions shown inthe drawing. This is particularly true of the stroke-bore ratio and thelever ratios shown in the drawing.

What is claimed is:

1. In a lever-type internal combustion engine, the combination of:

a. a crankshaft,

b. a plurality of power cylinders and air charging cylinderscommunicating with said power cylinders,

c. said power and air charging cylinders being each provided with apiston and a piston rod pivotally connected at its inner end with saidpiston, and

d. a lever system whereby the power cylinder pistons and piston rodsdrive the crankshaft,

c. said lever system consisting of the piston rods of the power and aircharging cylinders pivotally interconnected at their outer ends,

f. the piston rods of the air charging pistons being also operativelyconnected intermediate their ends to he crankshaft,

g. whereby said air charging cylinder piston rods function as secondclass levers between the power cylinder piston rods and the crankshaft,

h. The pivotal connection between the piston and inner end of the pistonrod of the air charging cylinders functioning as the fulcrum of thelever,

i. the pivotal connection between the outer end ofthe piston rod of theair charging cylinders and .the outer end of the piston rod of the powercylinders functioning as the force applyingpoint of the lever, and

j. the operative connection between the crankshaft and the piston rod ofthe air charging cylinders functioning as the load applying point of thelever.

2. A lever-type internal combustion engine in accordance with claim 1,wherein:

a. the power cylinders are arranged in linearly opposed pairs b. toenable each cylinder of each pair of power cylinders to absorb theinertial thrust of the piston and piston rod of the other cylinder.

3. A lever-type internal combustion engine in accordance with claim 1,wherein:

a. one air charging cylinder is provided for two power cylinders,

b. the volumetric capacity of each said air charging cylinder beingsufficient to concurrently scavenge and recharge both power cylinders.

4. A lever-type internal combustion engine in accordance with claim 3,wherein:

a. the power cylinders are provided with inlet and outlet ports, and

b. means for concurrently opening both ports,

c. whereby the power cylinders may concurrently be scavenged andrecharged by the air charging cylinders with which they are incommunication.

5. In a lever-type internal combustion engine, the combination of:

a. a plurality of power cylinders arranged in pairs,

b. each pair of power cylinders being coaxially aligned in opposedpositions,

c. pistons in each pair of opposed power cylinders,

d. piston rods pivotally connected at their respective inner ends tosaid pistons,

c. said piston rods being pivotally connected at their outer ends toeach other,

f. a plurality of air charging cylinders,

g. there being one air charging cylinder for each pair of opposed powercylinders,

h. a piston in each said charging cylinder,

i. a piston rod pivotally connected at its inner end to each saidcharging cylinder piston,

j. the outer end of the piston rod of each charging cylinder beingpivotally connected to the pivotally connected outer ends of the pistonrods of the corresponding pair of opposed power cylinders, and

k. a crankshaft having a plurality of crankpins, one for each aircharging cylinder,

l. the piston rod of each said charging cylinder being operativelyconnected intermediate its inner and outer ends to one ofthe crankpinsof the crankshaft,

m. whereby the piston rod of each said charging cylinder functions as alever of the second class between the piston rods of the correspondingpair of opposed power cylinders and the crankshaft,

n. the pivotal connection at the inner end of the piston rod of eachcharging cylinder comprising the fulcrum of the lever,

o. the pivotal connection at the outer end of the piston rod of eachcharging cylinder being the point at which force is applied to the leverby the piston rods of the pair of opposed power cylinders,

p. The operative connection intermediate the inner an outer ends of thepiston rod of each charging cylinder being the point of applied loadbetween the lever and the corresponding crankshaft pin.

6. A lever-type internal combustion engine in accordance with claim 5,wherein;

a. there are four pairs of opposed power cylinders, and

b. four air charging cylinders,

c. the four pairs of opposed power cylinders being arranged in parallelside-by-side relationship in a first common plane,

d. the four air charging cylinders being arranged in parallelside-by-side relationship in a second common plane, e. the crankshaftbeing also disposed in said second plane as well as in a third plane,

f. the first and third planes being parallel to each other andperpendicular to the second plane.

7. A lever-type internal combustion engine in accordance with claim 5,wherein:

a. the first plane in which the power cylinders are disposed and thethird plane in which the crankshaft is disposed are horizontal, and

b. the second plane in which the charging cylinders and crankshaft aredisposed is vertical.

8. A lever-type internal combustion engine in accordance with claim 5,wherein:

a. the stroke of the pistons of the power cylinders is relatively long,and

b. the bore of said power cylinders is relatively small,

c. such that the length of the stroke exceeds the diameter of the bore.

9. A lever-type internal combustion engine in accordance with claim 5,wherein:

a. each air charging cylinder communicates with two power cylinders,

b. the volumetric air charging capacity of each said charging cylinderbeing sufficient for concurrent scavenging and recharging of the twopower cylinders with which it communicates.

10. A lever-type internal combustion engine in accordance with claim 5,wherein:

a. the power cylinders are provided with inlet and outlet ports,

b. the pistons within said power cylinders being adapted to open andclose said inlet and outlet ports,

c. and being adapted to open both ports concurrently to enable thecommunicating air charging cylinder to concurrently scavenge andrecharge the power cylinders,

(1. said pistons being also adapted to close both ports for thecompression and power strokes of said power cylinders.

1. In a lever-type internal combustion engine, the combination of: a. acrankshaft, b. a plurality of power cylinders and air charging cylinderscommunicating with said power cylinders, c. said power and air chargingcylinders being each provided with a piston and a piston rod pivotallyconnected at its inner end with said piston, and d. a lever systemwhereby the power cylinder pistons and piston rods drive the crankshaft,e. said lever system consisting of the piston rods of the power and aircharging cylinders pivotally interconnected at their outer ends, f. thepiston rods of the air charging pistons being also operatively connectedintermediate their ends to the crankshaft, g. whereby said air chargingcylinder piston rods function as second class levers between the powercylinder piston rods and the crankshaft, h. The pivotal connectionbetween the piston and inner end of the piston rod of the air chargingcylinders functioning as the fulcrum of the lever, i. the pivotalconnection between the outer end of the piston rod of the air chargingcylinders and the outer end of the piston rod of the power cylindersfunctioning as the force applying point of the lever, and j. theoperative connection between the crankshaft and the piston rod of theair charging cylinders functioning as the load applying point of thelever.
 2. A lever-type internal combustion engine in accordance withclaim 1, wherein: a. the power cylinders are arranged in linearlyopposed pairs b. to enable each cylinder of each pair of power cylindersto absorb the inertial thrust of the piston and piston rod of the othercylinder.
 3. A lever-type internal combustion engine in accordance withclaim 1, wherein: a. one air charging cylinder is provided for two powercylinders, b. the volumetric capacity of each said air charging cylinderbeing sufficient to concurrently scavenge and recharge both powercylinders.
 4. A lever-type internal combustion engine in accordance withclaim 3, wherein: a. the power cylinders are provided with inlet andoutlet ports, and b. means for concurrently opening both ports, c.whereby the power cylinders may concurrently be scavenged and rechargedby the air charging cylinders with which they are in communication. 5.In a lever-type internal combustion engine, the combination of: a. aplurality of power cylinders arranged in pairs, b. each pair of powercylinders being coaxially aligned in opposed positions, c. pistons ineach pair of opposed power cylinders, d. piston rods pivotally connectedat their respective inner ends to said pistons, e. said piston rodsbeing pivotally connected at their outer ends to each other, f. aplurality of air charging cylinders, g. there being one air chargingcylinder for each pair of opposed power cylinders, h. a piston in eachsaid charging cylinder, i. a piston rod pivotally connected at its innerend to each said charging cylinder piston, j. the outer end of thepiston rod of each charging cylinder being pivotally connected to thepivotally connected outer ends of the piston rods of the correspondingpair of opposed power cylinders, and k. a crankshaft having a pluralityof crankpins, one for each air charging cylinder, l. the piston rod ofeach said charging cylinder being operatively connected intermediate itsinner and outer ends to one of the crankpins of the crankshaft, m.whereby the piston rod of each said charging cylinder functions as alever of the second class between the piston rods of the correspondingpair of opposed power cylinders and the crankshaft, n. the pivotalconnection at the inner end of the piston rod of each charging cylindercomprising the fulcrum of the lever, o. the pivotal connection at theouter end of the piston rod of each charging cylinder being the point atwhich force is applied to the lever by the piston rods of the pair ofopposed power cylinders, p. The operative connection intermediate theinner and outer ends of the piston rod of each charging cylinder beingthe point of applied load between the lever and the correspondingcrankshaft pin.
 6. A lever-type internal combustion engine in accordancewith claim 5, wherein: a. there are four pairs of opposed powercylinders, and b. four air charging cylinders, c. the four pairs ofopposed power cylinders being arranged in parallel side-by-siderelationship in a first common plane, d. the four air charging cylindersbeing arranged in parallel side-by-side relationship in a second commonplane, e. the crankshaft being also disposed in said second plane aswell as in a third plane, f. the first and third planes being parallelto each other and perpendicular to the second plane.
 7. A lever-typeinternal combustion engine in accordance with claim 5, wherein: a. thefirst plAne in which the power cylinders are disposed and the thirdplane in which the crankshaft is disposed are horizontal, and b. thesecond plane in which the charging cylinders and crankshaft are disposedis vertical.
 8. A lever-type internal combustion engine in accordancewith claim 5, wherein: a. the stroke of the pistons of the powercylinders is relatively long, and b. the bore of said power cylinders isrelatively small, c. such that the length of the stroke exceeds thediameter of the bore.
 9. A lever-type internal combustion engine inaccordance with claim 5, wherein: a. each air charging cylindercommunicates with two power cylinders, b. the volumetric air chargingcapacity of each said charging cylinder being sufficient for concurrentscavenging and recharging of the two power cylinders with which itcommunicates.
 10. A lever-type internal combustion engine in accordancewith claim 5, wherein: a. the power cylinders are provided with inletand outlet ports, b. the pistons within said power cylinders beingadapted to open and close said inlet and outlet ports, c. and beingadapted to open both ports concurrently to enable the communicating aircharging cylinder to concurrently scavenge and recharge the powercylinders, d. said pistons being also adapted to close both ports forthe compression and power strokes of said power cylinders.